﻿using System.Security.Cryptography;
using System.Text;

namespace PMS.WebApi.Utils
{
    public class EncryptHelper
    {
        // 提供8个字符作为DES密钥（程序自动截取前8个字符） 
        private static string key = "lds2@pms";

        /// 
        /// DES对称加密解密的密钥
        ///  
        public static string Key
        {
            get
            {
                return key;
            }
            set
            {
                key = value;
            }
        }

        /// 
        /// MD5 加密（不可逆加密）
        /// 
        /// 要加密的原始字串
        ///  
        public static string MD5Encrypt(string pass)
        {
            System.Security.Cryptography.MD5 md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
            byte[] bytResult = md5.ComputeHash(System.Text.Encoding.UTF8.GetBytes(pass));
            md5.Clear();
            string strResult = BitConverter.ToString(bytResult);
            strResult = strResult.Replace("-", "");
            return strResult;

        }

        /// 
        /// SHA1 加密（不可逆加密）
        /// 
        /// 要加密的原始字串
        ///  
        public static string SHA1Encrypt(string pass)
        {
            System.Security.Cryptography.SHA1 sha1 = new System.Security.Cryptography.SHA1CryptoServiceProvider();
            byte[] bytResult = sha1.ComputeHash(System.Text.Encoding.UTF8.GetBytes(pass));
            sha1.Clear();
            string strResult = BitConverter.ToString(bytResult);
            strResult = strResult.Replace("-", "");
            return strResult;

        }

        /// 
        /// DES加密字符串
        /// 
        /// 待加密的字符串
        /// 加密成功返回加密后的字符串，失败返回源串 
        public static string DESEncrypt(string encryptString)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(key.Substring(0, 8));
                byte[] rgbIV = rgbKey;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                cStream.Close();
                return Convert.ToBase64String(mStream.ToArray());
            }
            catch
            {
                return encryptString;
            }
        }

        /// 
        /// DES解密字符串
        /// 
        /// 待解密的字符串
        /// 解密成功返回解密后的字符串，失败返源串 
        public static string DESDecrypt(string decryptString)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(key.Substring(0, 8));
                byte[] rgbIV = rgbKey;
                byte[] inputByteArray = Convert.FromBase64String(decryptString);
                DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                cStream.Close();
                return Encoding.UTF8.GetString(mStream.ToArray());
            }
            catch
            {
                return decryptString;
            }
        }

        /// 
        /// DES加密字符串
        /// 
        /// 待加密的字符串
        /// 加密authKey
        /// 加密成功返回加密后的字符串，失败返回源串 
        public static string DESEncrypt(string encryptString, string authKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(authKey.Substring(0, 8));
                byte[] rgbIV = rgbKey;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                cStream.Close();
                return Convert.ToBase64String(mStream.ToArray());
            }
            catch
            {
                return encryptString;
            }
        }
        /// 
        /// DES解密字符串
        /// 
        /// 待解密的字符串
        /// 解密authKey
        /// 解密成功返回解密后的字符串，失败返源串 
        public static string DESDecrypt(string decryptString, string authKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(authKey.Substring(0, 8));
                byte[] rgbIV = rgbKey;
                byte[] inputByteArray = Convert.FromBase64String(decryptString);
                DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                cStream.Close();
                return Encoding.UTF8.GetString(mStream.ToArray());
            }
            catch
            {
                return decryptString;
            }
        }

        /// 
        /// 将普通字符串编码为BASE64字串
        /// 
        /// 源字符串
        ///  
        public static string Base64Encode(string str)
        {
            return Convert.ToBase64String(Encoding.UTF8.GetBytes(str));
        }

        /// 
        /// 解码BASE64字串
        /// 
        /// Base64字串
        ///  
        public static string Base64Decode(string base64Str)
        {
            return Encoding.UTF8.GetString(Convert.FromBase64String(base64Str));
        }
    }
}
